Unnerve

The "Each opponent" clause is the whole story here, and it points to the format this card was actually built for: the multiplayer table, where one four-mana sorcery strips two cards from every opponent at once. Read that way, the rate stops looking like a worse Mind Rot and starts looking like a fan effect that scales with the pod. Against three opponents that is six cards gone for one card spent, and the four-mana cost is the tax black pays for that breadth. The trouble is the design discipline good discard depends on, which is timing: hand attack wants to land early, while hands are full and the choices still hurt, because every turn you wait is a turn each opponent spends emptying the very resource you are attacking. Four mana pushes this past that window almost by definition, and the symmetry that helps it in a crowd works against it heads-up, where the same investment buys two cards off a single opponent who has had three turns to dump a hand worth attacking. Compared to the surgical economy of Hymn to Tourach, which strips at random for half the mana before the opponent can react, Unnerve is built wide rather than sharp. It is a clean illustration of black's recurring lesson about disruption: discard scales inversely with the mana you sink into it, and the more players you are trying to hit, the more you are paying for reach instead of pressure.